The Montreal Protocol regulates ozone-depleting substances and is among the rare treaties with universal ratification

Background

Standing background on the ozone treaty. Adopted on 16 September 1987, the Montreal Protocol is to date one of the rare treaties to achieve universal ratification. It regulates the production and consumption of nearly 100 man-made chemicals referred to as ozone depleting substances (ODS). The Kigali Amendment, adopted on 15 October 2016, added HFCs (hydrofluorocarbons) to the controlled list and approved a timeline for their gradual reduction by 80-85 per cent by the late 2040s. It entered into force on 1 January 2019 for ratifying nations.